Properties and tunability of band gaps in innovative reentrant and star-shaped hybrid honeycomb metamaterials

In this paper, a new kind of acoustic metamaterials, the reentrant and star-shaped hybrid honeycomb metamaterials (RSHHM) were proposed, in which the elastic rubber coated mass inclusions were added to create the low-frequency band gaps. Formation mechanisms for the band gaps and effects of the geometrical parameters and the number of filled mass inclusions on band gaps of the RSHHM were systematically studied by combining the FE method and the Bloch's theorem. Meanwhile, transmissions of the finite-sized sandwich panels with the core of RSHHM were calculated to verify the vibration attenuation performances of the RSHHM. In addition, tunability of band gaps of the RSHHM was explored by exerting large deformations on the RSHHM endowed them with almost incompressible hyperelastic constituent materials. Numerical results showed, by rationally choosing the geometrical parameters, mass inclusions and the constituent materials, the RSHHM proposed in this paper could have tunable high and low frequency plane wave attenuation characteristics. The research of this paper provides a new strategy for the design of acoustic structures and devices with dynamic tunable band gaps properties.

Automated summary

This study introduces a new type of acoustic metamaterials, RSHHM, with tunable high and low frequency plane wave attenuation characteristics. By optimizing the geometrical parameters and mass inclusions, as well as applying large deformations, the band gaps of RSHHM can be adjusted for dynamic tunability.